Human induced enviremental changes can affect living things at which levels

In a relatively small iguana population the allelic frequency is tracked for three generations. webbing is a recessive allele; no webbing is the dominant allele. during one very rainy spring and summer, a flood washes all the iguana without webbed feet out to sea. by the fall, and three generations later, you have the gene pool seen here.

Ialready know the answers to these questions and they are on the attachment. but i just need to know why that answer is the correct one. plz asap! this is for a report that i need to email by 10!

What processes would you expect to be key in the production of yogurt ?